App Intents: Siri does not recognize currency amounts

Hello,

I am implementing an App Intent which asks the user for a currency amount:

private func loadAmountList(forNumber number: String) async throws -> [NSDecimalNumber] {...}

@MainActor func perform() async throws -> some IntentResult & ShowsSnippetView {

    let list = try await loadAmountList(forNumber: fixedNumber).compactMap {
    currencyFormatter.string(from: $0)
}

    throw $amount.needsDisambiguationError(among: list, dialog: "app_intent_sim_amount_prompt")
}

If I start this intent from Siri, the attached screenshot is shown, but no matter what I say ("10 EURO", "ten", "10", "10€"...) Siri never understands anything and keep reshowing the dialog over and over again. If instead I tap any of the choices then the intent execution proceeds currectly.

How can I solve the problem? Thanks